During the 2012 funding period, we addressed the following: In collaboration with our colleagues from the Walter Reed Army Institute of Research (T.Balkin and D. Picchioni, we use the L-1-11Cleucine positron emission tomography method to measure rCPS in the same subject during three consecutive scans in normal wakefulness, sleep-deprived wakefulness, and sleep. These studies will test the idea that protein synthesis is elevated during sleep to restore brain infrastructure. Subjects are healthy male and female volunteers between the ages of 18 and 28 y. To date we have complete data sets on seven subjects who spent between 30-68 weighted % time in slow wave sleep during the third scan. We have measured rCPS in 15 regions and the brain as a whole, and preliminary results indicate trends for elevated rCPS during sleep in some brain regions. We are also determining whether sleep-dependent increases in rCPS are associated with sleep-dependent improvements in memory. We use the texture discrimination task to assess learning and memory. Improvement on performance of this task has been demonstrated to depend on sleep. Because the texture discrimination task is retinotopically specific, training in one hemisphere (due to stimuli in the contralateral visual field) does not improve performance in the opposite hemisphere. Therefore, we determine changes in rCPS in the trained hemisphere of the primary visual cortex and use the untrained hemisphere as a control. Subjects are healthy males and females between the ages of 18 and 28y. The task is administered in the morning, subjects are randomized to nap or no-nap groups during the positron emission tomography scan at midday, and the task is re-administered in the evening. The stimulus of the task is always in the lower half of the visual field and we randomize the stimulated side (left or right). We hypothesize that an increase in rCPS in the trained hemisphere will be observed in subjects who spent a significant time in SWS during the nap. Our preliminary results in six subjects indicate that rCPS is indeed increased in the part of primary visual cortex that maps to the stimulus.